Melon fly, Bactrocera cucurbitae (Coquilette) and oriental fruit fly, B. dorsalis (Hendel)(Diptera: Tephritidae) are the two most economical fruit fly pests of many fruit and fruit vegetables. Field sanitation, male mass annihilation, and weekly protein bait spray application are the major components of Hawaii Area wide Fruit Fly Integrated Pest Management Program. Cuelure and methyl eugenol treated cotton wicks are used for population monitoring and mass annihilation of these two species respectively. Two field experiments were conducted during 2003-2004 to compare ready to use plastic matrix plugs with lure in the cotton wicks for their efficiency and longevity. Both cotton wick and plastic matrix plugs contained either 2 g a. i. cuelure or 2 g a. i. methyl eugenol. No significant differences were observed for more than one year between fresh and weathered lure, and plastic and cotton treated cuelure, nor there was any significant interaction between the two factors in terms of the numbers of melon fly caught. However, methyl eugenol in either plastic or cotton formulation caught significantly less number of oriental fruit flies after five weeks of field weathering, but there was no significant difference between the plastic and cotton formulation.